B31.3 App D Note (1)states "Stress intensification and flexibility factor data in Table D300 are for use in the absence of more directly applicable data (see para. 319.3.6). Their validity has been demonstrated for D/ T ≤ 100."

Now, even with the avaiability of FEATOOLS at their disposal, if any engineering A/E firm considers App-D SIF & k values in a non-conservative manner as FESIF gives higher SIF than App D values, is the intent of note 1 above is not violated ? If so, is the responsibility of the safety of the underdesigned hardware falling on the A/E firm ?

I wish to get the opinion of our elders here as in B31.3 jurisdiction we are working with thin cryogenic piping of large diameter of appreciably high pressure.

regards,
sam